Medical graft connector or plug structures, and methods of making and installing same

ABSTRACT

A medical graft connector or plug is made, for example, by cutting end portions of a tube of highly elastic material axially at numerous locations spaced circumferentially around the tube to produce a plurality of fingers which extend axially from each end of an uncut medial portion of the tube. The fingers are deflected radially outwardly from the medial portion and set in that condition. For a graft connector, the medial portion is coaxially connected to an end portion of a tubular graft. The connector is then installed through an aperture in the side wall of a patient&#39;s tubular body conduit, for example, by using a delivery tube in which the fingers are elastically deflected back to approximately their initial positions. When the delivery conduit is withdrawn from the connector, the fingers spring out to engage the inner and outer surfaces of the body conduit wall. For a plug, the medial portion is occluded and then the structure is installed through the aperture to be plugged in a manner similar to installation of the connector.

BACKGROUND OF THE INVENTION

[0001] This invention relates to structures that can be used to makeconnections between tubular medical grafts and a patient's tubular bodyconduits. The structures of the invention can alternatively beconstructed for use as medical plugs (e.g., to close atrial orventricular septal defects). The invention also relates to methods formaking and using the structures mentioned above.

[0002] Tubular grafts are frequently needed in medical procedures. Forexample, a coronary bypass procedure may involve the installation of atubular graft between an aperture that has been formed in the side wallof the aorta and an aperture that has been formed in the side wall of acoronary artery downstream from an occlusion or blockage in that artery.Each end of the graft must be connected to the side wall of either theaorta or the coronary artery. Each such connection must extend annularlyaround the associated end of the graft conduit and be fluid-tight sothat no blood will leak out. One common way to produce such connectionsis by suturing. It will be appreciated, however, that making suchconnections by suturing can be extremely difficult, time-consuming, anddependent on the skill of the physician for the quality of the results.There is also increasing interest in less invasive procedures which tendto impose constraints on the physician's access to the sites at whichgraft connections must be made and thereby make it more difficult oreven impossible to use suturing to make such connections (see, forexample, Goldsteen et al. U.S. patent application Ser. No. 08/745,618,filed Nov. 7, 1996, Sullivan et al. U.S. patent application Ser. No.08/844,992, filed Apr. 23, 1997, and Sullivan et al. U.S. patentapplication Ser. No. 08/869,808, filed Jun. 5, 1997, all of which arehereby incorporated by reference herein in their entireties). Varioustypes of mechanical connectors have been developed to reduce oreliminate the need for suturing, but improvements are constantly soughtfor such mechanical connectors with respect to considerations such asease and speed of use, ease of manufacture, strength and permanence ofthe resulting connection, etc.

[0003] Plugs are also needed in a variety of medical procedures. Forexample, it may be necessary to plug an atrial or ventricular septaldefect in the heart of a new-born child. Again, improvements areconstantly sought for plugs which can be easily and quickly installedusing minimally invasive procedures.

[0004] In view of the foregoing, it is an object of this invention toprovide improved and simplified graft connectors.

[0005] It is another object of this invention to provide improved andsimplified medical plugs.

[0006] It is still another object of this invention to provide improvedand simplified methods of making structures that can be used as eithermedical graft connectors or plugs.

[0007] It is yet another object of this invention to provide improvedand simplified methods for installing medical graft connectors or plugs.

SUMMARY OF THE INVENTION

[0008] These and other objects of the invention are accomplished inaccordance with the principles of the invention by providing a connectoror plug structure preferably formed by starting from a tube of highlyelastic material such as nickel and titanium alloy (nitinol) metal. Eachend portion of the tube is cut substantially axially at numerouslocations spaced circumferentially around the tube to produce aplurality of fingers that extend substantially axially from each end ofa remaining medial portion of the tube. The fingers at each end of themedial portion are then deflected so that they extend substantiallyradially out from the medial portion, and the fingers are set (e.g., bya heat treatment) in that deflected condition. For use of the structureas a graft connector, the medial portion is attached substantiallycoaxially to an end portion of a graft conduit. For use of the structureas a plug the medial portion of the tube is filled with a suitableplugging material or structure.

[0009] To install the graft connector or plug in a patient the fingersat each axial end of the medial portion may be elastically deformed backtoward their initial condition (in which the fingers extendsubstantially axially from the ends of the medial portion). Thestructure may then be inserted in a delivery tube, which may maintainthe fingers in their substantially axially extending condition. Thedelivery tube may then be inserted through the aperture in the side wallof the patient's tubular body conduit to which the end of the graftconduit is to be attached, or through the aperture in the patient'stissue structure that is to be plugged. The delivery conduit may then beremoved from around the connector or plug structure. This releases thefingers at each end of the medial portion to spring out on respectiveopposite sides of the tissue structure to which the connection is to bemade, or to which the plug is to be applied.

[0010] In some cases fingers may only be formed in one end of a startingtube. A connector may then be provided using two such tubes concentricwith one another and with a graft conduit. In such an assembly thefingers on the two tubes extend from generally opposite axial ends ofthe assembly. Two such tubes may be similarly used to make a plug,although in this case the graft conduit is omitted and the interior ofthe structure is filled with a plugging material or structure.

[0011] As an alternative or addition to use of a delivery tube toreleasably hold the fingers substantially parallel to the longitudinalaxis of a connector or plug, another structure may be removably placedaround the fingers. Examples of such another structure include a collaror a strand of material such as wire or suture material.

[0012] Further features of the invention, its nature and variousadvantages will be more apparent from the accompanying drawings and thefollowing detailed description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a side elevational view of an illustrative embodiment ofa starting component for a structure of this invention.

[0014]FIG. 2 is an end elevational view of the component of FIG. 1.

[0015]FIG. 3 is a side elevational view of the FIG. 1 component aftersome processing in accordance with the invention.

[0016]FIG. 4 is a sectional view of the FIG. 3 component after furtherprocessing in accordance with the invention.

[0017]FIG. 5 is an end elevational view of the FIG. 4 component.

[0018]FIG. 6 is a simplified side elevational view of the FIG. 4component with a graft conduit added so that the FIG. 4 component can beused as a connector for the graft conduit.

[0019]FIG. 7 is a simplified, partly cut away, side elevational view ofthe FIG. 6 assembly in illustrative apparatus for use in installing theFIG. 6 assembly in a patient.

[0020]FIG. 8 illustrates use of the FIG. 7 apparatus to install the FIG.6 assembly in a patient.

[0021]FIG. 9 is a simplified sectional view of the FIG. 4 component withplug material or structure added so that the FIG. 4 component can beused as a plug.

[0022]FIG. 10 is a view similar to FIG. 7, but for the plug embodimentof FIG. 9.

[0023]FIG. 11 is a view somewhat like FIG. 8, but for the plugembodiment of FIGS. 9 and 10.

[0024]FIG. 12 is another view somewhat like FIG. 11, but showing a fullyinstalled plug of the type shown in FIG. 9.

[0025]FIG. 13 is another view similar to FIG. 3 showing an illustrativemodification of a FIG. 3 type structure in accordance with theinvention.

[0026]FIG. 14 is another view similar to a portion of FIG. 4 showing anillustrative modification of a FIG. 4 type structure in accordance withthe invention.

[0027]FIG. 15 is a sectional view somewhat like FIG. 8 showingillustrative modifications in accordance with the invention.

[0028]FIG. 16 is a simplified sectional view showing still otherillustrative modifications in accordance with the invention.

[0029]FIG. 17 is a simplified sectional view showing an assembly similarto the assembly shown in FIG. 6, but with an illustrative modificationin accordance with the invention.

[0030]FIG. 18 is a simplified sectional view somewhat like FIG. 4 whichis useful in explaining an illustrative modification in accordance withthis invention.

[0031]FIG. 19 is a view somewhat like FIG. 7 or FIG. 10 for the modifiedstructure of FIG. 18.

[0032]FIG. 20 is a simplified sectional view showing an illustrativeprecursor structure for embodiments of the type illustrated by FIGS. 18and 19.

[0033]FIG. 21 is a simplified elevational view showing anotherillustrative precursor structure for embodiments of the type illustratedby FIGS. 18 and 19.

[0034]FIG. 22 is a simplified sectional view similar to FIG. 15 showingother illustrative modifications in accordance with the invention.

[0035]FIG. 23 is a simplified elevational view similar to FIG. 3 showingmore illustrative modifications in accordance with the invention.

[0036]FIG. 24 is another simplified elevational view similar to FIG. 3showing still more illustrative modifications in accordance with theinvention.

[0037]FIG. 25 is a simplified sectional view showing an illustrativealternative to apparatus of the type shown in FIG. 7.

[0038]FIG. 26 is a simplified elevational view illustrating anotherpossible modification of structures in accordance with the invention.

[0039]FIG. 27 is a simplified elevational view somewhat like FIG. 3showing another illustrative embodiment of the invention.

[0040]FIG. 28 is a simplified sectional view illustrating use ofapparatus of the type shown in FIG. 27.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] An illustrative starting component for the connector or plugstructures of this invention is a hollow tube 10 as shown in FIGS. 1 and2. Tube 10 may have any length, diameter, and wall thickness suitablefor the intended use of the finished connector or plug structure. Foruse as a cardiac bypass graft connector, for example, tube 10 may have adiameter of about 4.0 millimeters, a wall thickness of about 0.003inches, and a length of about 7.0 millimeters. It will be understood,however, that these specific dimensions are only exemplary, and that anyother dimensions can be used instead if desired. The material of tube 10is preferably highly elastic. A particularly preferred material isnickel titanium alloy (nitinol) metal (which can be per seconventional), but other materials such as stainless steel orthermoplastics can be used instead if desired.

[0042] A first step in processing tube 10 in accordance with theinvention is to cut into it substantially axially at many locations 12spaced circumferentially around each axial end portion as shown in FIG.3. Cuts 12 reduce starting tube 10 to a plurality of fingers 14extending substantially axially from each end of an uncut medial tubeportion 16. Cuts 12 may be made by any suitable technique such aselectron discharge machining (“EDM”), laser cutting, or etching. Thelength of medial portion 16 may be selected based on the intended use ofthe structure. For example, the length of medial portion 16 may beselected to correspond to the thickness of the patient's body tissuethrough which the medial portion will extend. Illustrative lengths formedial portion 16 are in the range from about 0.2 millimeters to about4.0 millimeters. The length of fingers 14 may also be selected based onthe intended use of the structure. Illustrative lengths for fingers 14are in the range from about 1.0 millimeter to about 10.0 millimeters.

[0043] The next step is to deflect fingers 14 to approximately thepositions that it is desired for them to have in the finished andinstalled connector or plug structure. For example, FIGS. 4 and 5 showdeflecting fingers 14 substantially radially out from the end of medialportion 16 that each finger is attached to. Although FIGS. 4 and 5 showthe angle A between each finger 14 and the adjacent axially extendingsurface of medial portion 16 as approximately 90°, it will be understoodthat a wide range of angles A (e.g., in the range from about 45° toabout 120°) can be used. Indeed, the angle of deflection of variousfingers 14 can be different if desired. In addition, fingers 14 can becurved (e.g., concave curved as viewed from a plane extending radiallyout from medial portion 16) rather than straight if desired, and indeedoutward curvature of the fingers can be used in place of outwarddeflection by a definite angle A. For example, the free ends of thefingers 14 at one or both ends can curve toward or even overlap the freeends of the fingers at the other end. FIG. 6 and some subsequent FIGS.show examples of such curvature of fingers 14. FIG. 17 shows an exampleof overlapping fingers 14. In general, however, fingers 14 will bedeflected so that they have at least a component of radially outwardextension from medial portion 16. For convenience and simplicity hereinit will therefore sometimes be said that fingers 14 extend radially outfrom medial portion 16, even though it will be understood that thiswording includes (1) fingers having only a component of such radiallyoutward extension, and (2) fingers that are either substantiallystraight or curved.

[0044] It will also be appreciated that it may be desirable to deflectfingers 14 beyond their desired final positions so that when they aresubsequently released during deployment, they will resiliently bear onthe tissue in which the connector or plug is installed in their effortto return to the positions to which they have been deflected in thisstep of their manufacture. For example, if FIG. 4 shows the desiredfinal position of fingers 14 in use in a patient (i.e., angle A=90°), itmight be desirable at this stage in the manufacturing process to deflectfingers 14 more than is shown in FIG. 4 (e.g., to angle A=60°) toincrease the security with which fingers 14 will engage tissuesurrounding medial portion 16. Nevertheless, for convenience andsimplicity herein it will sometimes be said that in this manufacturingstep fingers 14 are deflected to (or at least to) approximately theirintended final positions, it being understood that this wording includesdeflecting fingers beyond the actual intended final positions.

[0045] When fingers 14 have been deflected to approximately their finalintended positions (e.g., as shown in FIGS. 4 and 5), fingers 14 are setin those positions. For example, a heat treatment may be applied to thestructure to set fingers 14 in their deflected positions.

[0046] FIGS. 6-8 show use of a structure of the type shown in FIGS. 4and 5 to provide a connector 20 for an end of graft conduit 30. (Thepossible alternative use of structures of the type shown in FIGS. 4 and5 as a plug rather than a graft connector will be discussed afterexplanation of the connector embodiment is substantially complete.)Graft conduit 30 may be natural conduit (e.g., a relocated portion ofthe patient's tubular body tissue), artificial conduit (e.g., of thetype shown in above-mentioned application Ser. No. 08/745,618), or acomposite of natural and artificial conduits.

[0047] In the illustrative embodiment shown in FIG. 6 an axial endportion of graft conduit 30 is inserted substantially coaxially into andattached to medial portion 16. Depending on the materials of components20 and 30, they may be secured together by any suitable means such assuturing, adhesive, welding, etc.

[0048] The next step in use of the graft 30 and connector 20 is toinsert that assembly into a delivery tube 40 as shown in FIG. 7. Tube 40is preferably slightly larger in diameter than medial portion 16 orgraft conduit 30. To fit structure 20 into tube 40 fingers 14 areresiliently deflected back toward their initial positions as axialextensions from the ends of medial portion 16 as shown in FIG. 7. Inother words, fingers 14 are elastically deflected inwardly towardparallelism with a central longitudinal axis of medial portion 16. Ifconnector 20 is made of nitinol, temporary super-cooling of theconnector may be used at this stage to facilitate assembly of components20 and 30 in delivery tube 40 (assuming that graft conduit 30 cantolerate proximity to super-cooled connector 20). Super-cooling nitinolmakes it very plastic so that fingers 14 can be straightened out and sothat they will hold that shape for insertion of components 20 and 30into tube 40. When connector 20 warms up again, it “remembers” the shapeit was given during the step in which the fingers were set after beingradially outwardly deflected.

[0049] The next step in use of the assembly shown in FIG. 7 is to insertdelivery tube 40 through an aperture in the side wall of the patient'stubular body conduit (50 in FIG. 8) to which graft conduit 30 is to beconnected by connector 20. For example, a tapered distal end portion ofdelivery tube 40 (shown on the right in FIG. 7) may be used to help tube40 enter the aperture in tubular body conduit side wall 52. Elements 20,30, and 40 are preferably positioned relative to side wall 52 so thatmedial portion 16 is approximately centered on side wall 52. This placesthe fingers 14 at one axial end of medial portion 16 inside conduit 50,while the fingers 14 at the other end of medial portion 16 are outsideconduit 50.

[0050] The next step is illustrated by FIG. 8 and involves thewithdrawal of delivery tube 40 from the aperture in side wall 52, whilecomponents 20 and 30 are held stationary relative to side wall 52. Asdelivery tube 40 is thus withdrawn, the fingers 14 on the inside ofconduit 50 are gradually released to resiliently spring out inside sidewall 52 around the aperture through that wall. Thereafter, as deliverytube 40 continues to be retracted, the finger 14 on the outside ofconduit 50 are also released to resiliently spring out outside side wall52 around the aperture through that wall. Thus the final condition ofconnector 20 is as shown in FIG. 8 (although of course delivery tube 40is ultimately completely withdrawn from the patient). The fingers 14 onthe inside of conduit 50 prevent the connector and graft conduit frompulling out of the aperture in side wall 52. The fingers 14 on theoutside of conduit 50 prevent the connector and graft conduit fromprotruding undesirably far into conduit 50.

[0051] Although FIGS. 7 and 8 show inserting connector 20 into theaperture in the side wall 52 of conduit 50 from outside that conduit,connector 20 could alternatively be inserted from inside the lumen ofconduit 50. In that case connector 20 would typically be located at amedial position in delivery tube 40, with graft conduit 30 extendingfrom the connector in the distal direction along the interior of tube40. Tube 40 would then be inserted intraluminally into conduit 50 untilthe location of the aperture in wall 52 is reached. Tube 40 would thenbe passed out of the aperture in wall 52 until medial portion 16 iscentered on wall 52. Components 20 and 30 would then be held stationaryrelative to conduit 50 while tube 40 is pulled back proximally via thelumen of conduit 50, thereby exposing graft conduit 30 outside conduit50 and similarly exposing connector 20 so that fingers 14 can spring outand engage the inner and outer surfaces of side wall 52 around theaperture in that side wall. A separate axially extending pusher orholder structure may be needed inside tube 40 to help hold components 20and 30 stationary as described above while tube 40 is pulled backproximally.

[0052]FIG. 9 shows an alternative embodiment in which a structure of thetype shown in FIGS. 4 and 5 is adapted for use as a plug 60. In thisalternative medial portion 16 is substantially filled or occluded with aplug material or structure 70 such as silicone or thermoplastic. Plug 60is then inserted in a delivery tube 40 as shown in FIG. 10 insubstantially the same way that tube 40 is used with component 20 inFIG. 7.

[0053] The next step in the use of assembly 40/60 is to insert tube 40through the aperture in the tissue structure 80 that is to be plugged asshown in FIG. 11. As in the previously described connector embodiment,assembly 40/60 is preferably positioned relative to tissue structure 80so that the fingers 14 extending from one axial end of medial portion 16are on one side of structure 80, and so that the fingers 14 extendingfrom the other axial end of medial portion 16 are on the other side ofstructure 80.

[0054] The next step is to withdraw tube 40 from the aperture in tissuestructure 80, while holding plug 60 substantially stationary relative tostructure 80. To hold plug 60 stationary in this manner, a holder tube(not shown) may be inserted into tube 40 until the distal end of theholder tube bears on plug structure 70. Then the holder tube can be heldstationary relative to tissue structure 80 while tube 40 is withdrawn.As tube 40 is withdrawn, the fingers 14 on the right-hand side ofstructure 80 as viewed in FIGS. 11 and 12 are gradually released tospring resiliently out against that side of structure 80. Furtherwithdrawal of tube 40 allows the fingers on the left-hand side ofstructure 80 to spring resiliently out against that side of structure80. The completed plug installation is as shown in FIG. 12.

[0055] As in the case of connector 20, plug 60 can be inserted into theaperture in tissue structure 80 from either side of that tissuestructure, and tube 40 can similarly be withdrawn in either direction.For example, if tissue structure 80 is the wall of a conduit or chamber,plug 60 can be installed from either the inside or outside of thatconduit or chamber, and tube 40 can be withdrawn via either the insideor outside of that conduit or chamber.

[0056] Manufacture of the connector or plug structures described aboveis greatly facilitated by the fact that elements 14 and 16 all come fromone starting structure (i.e., tube 10). Elements 14 and 16 are thereforeintegral at all times, and there is no need to attempt to assemblerelatively small fingers 14 on another component. Use of the connectoror plug structures of this invention is extremely easy because all thatis required is to properly position the connector or plug relative tothe appropriate tissue of the patient and then withdraw the deliverytube 40 from around the connector or plug. Fingers 14 automaticallyspring out into the positions required to complete and secure theconnector or plug.

[0057] If desired, medial portion 16 can be perforated at any suitabletime during the course of manufacturing a connector or plug inaccordance with this invention. For example, FIG. 13 shows manyperforations 16 b in medial portion 16, thereby effectively reducing themedial portion to an open mesh of members 16 a. Such perforation ofmedial portion 16 may increase its flexibility (e.g., axially andradially) and therefore its long-term acceptability in the patient'sbody. The radial compliance of a flexible connector or plug (i.e. theability of such a structure to resiliently increase or decrease incircumference) is believed to be beneficial with respect to long-termbody circuit lumen patency. Increased flexibility and radial complianceof medial portion 16 may also facilitate delivery and/or installation ofthe connector or plug. For example, flexibility of medial portion 16 mayallow a connector or plug to be resiliently circumferentially compressedto a relatively small size to facilitate delivery of the connector orplug to an installation site (e.g., delivery through the lumen of apatient's body conduit). After the connector or plug has been deliveredto the desired site in the patient's body in its circumferentiallycompressed size, the connector or plug is released from the deliveryapparatus so that it can automatically return to its original largersize. In the case of a connector for a natural tissue graft, perforationof medial portion 16 may allow the tissue of the graft and conduit towhich the graft is connected to grow together through the perforations.

[0058] Perforation of medial portion 16 may also allow that portion of aconnector or plug to exert resilient, radially outward force onsurrounding tissue on a long-term basis after the connector or plug hasbeen installed. This may be useful for such purposes as firmerengagement of the surrounding tissue, reduced potential for fluidleakage around the connector or plug, etc. For example, if the elasticrecoil of the surrounding tissue diminishes over time or if the tissueis relatively non-elastic due to disease or age, sealing between thetissue and the connector or plug may be reduced. In such cases,resilient outward expansion of the connector or plug can be helpful incompensating for deficiencies of the tissue. A connector or plug with aperforated medial portion 16 can resiliently expand to fill any openingthat may otherwise tend to develop between portion 16 and thesurrounding tissue if and when the elastic recoil of the tissuediminishes.

[0059] Whereas the depicted connector and plug embodiments are round,other shapes (e.g., ellipses, polygons, etc.) are equally possible.Similarly, the ends of medial portion 16 do not have to be perpendicularto the longitudinal axis of the connector or plug structure.Particularly in the case of connectors, it may be desired to have one orboth ends of medial portion 16 skewed relative to the longitudinal axisof the connector (i.e., so that the longitudinal axis is notperpendicular to a plane defined by the skewed end of medial portion16). The free ends of the adjacent fingers 14 may then be similarlyskewed. Such skewing of portions of the connector may facilitateconnecting the end of a graft to the side wall of a patient's bodyconduit at an angle other than 90° to that side wall. These and otherillustrative examples of modifications, alternatives, and enhancementsin accordance with the invention will now be discussed in more detailwith reference to FIGS. 14-28.

[0060]FIG. 14 shows that the free ends of fingers 14 can be sharplypointed as indicated at 14 a to facilitate engagement and or penetrationof tissue by the fingers. This can be done, for example, by sharpeningthe associated axial end of the starting tube 10 to a sharp annular edgeprior to making cuts 12 as shown in FIG. 3.

[0061]FIG. 15 shows the free ends of the fingers 14 that are generallyon the inside of conduit 50 penetrating and passing through the conduitwall 52 to more firmly secure connector 20 to conduit 50. In addition,FIG. 15 shows that the free ends of the above-mentioned fingers 14 maybe provided with barbs 14 b (somewhat like the barbs on fishing hooks)that strongly resist withdrawal of the fingers after the fingers havepenetrated the tissue of conduit wall 52. FIG. 15 still further showsthat the fingers 14 on the inside of conduit 50 in a finished connectionmay be different from the fingers 14 on the outside of conduit 50. Forexample, the fingers 14 on the inside of conduit 50 may be longer,curved and sharply pointed for tissue penetration, and barbed as at 14b, while the fingers 14 on the outside of conduit 50 may be shorter,straighter, blunter, not barbed, and therefore not as adapted for tissuepenetration. Such differences between the inner and outer fingers 14 mayreflect different performance characteristics needed of them. Fluidpressure inside conduits 30 and 50 may attempt to force conduit 30 awayfrom conduit 50, thereby necessitating relatively strong inner fingers14. Concomitantly, there may be little tendency of conduit 30 to extendfarther into conduit 50, so that outer fingers 14 can be relativelyweak. Other differences that can be made between inner and outer fingers14 include differences in number, spacing, width, etc.

[0062]FIG. 16 illustrates a point made earlier; namely, that a connectoror plug in accordance with this invention can have a cross sectionalshape other than round. In the particular example shown in FIG. 16 theconnector or plug has an elliptical cross section, with the major axisof the ellipse substantially aligned with the longitudinal axis ofconduit 50. In addition, FIG. 16 shows that different fingers 14 ateither or both axial ends of medial portion 16 can have differentlengths. In the particular example shown in FIG. 16 the fingers 14 thatare more nearly aligned with the longitudinal axis of conduit 50 arelonger than the fingers that are more nearly perpendicular to thelongitudinal axis of conduit 50. To produce fingers 14 of differentlengths, one or both axial ends of the starting tube 10 can beappropriately shaped prior to making cuts 12, or the free ends of thefingers can be trimmed after cuts 12 have been made.

[0063]FIG. 17 illustrates another possibility mentioned earlier; namely,that the fingers 14 extending from axially opposite ends of medialportion 16 may be deflected and set so that their free ends overlap.When a connector or plug made in this way is installed in a patient,this construction of fingers 14 helps to increase the contact areabetween fingers 14 and the tissue between them, as well as compressionof the tissue between the fingers.

[0064] It may desirable to make fingers 14 so that their flexuralstiffness (especially in directions radial of medial portion 16) variesin a predetermined way along the length of each finger. This feature canbe used, for example, to cause the fingers to assume a more nearlycylindrical shape when they are deflected for insertion into a deliverytube 40. Thus FIG. 18 shows a connector or plug which makes use of thispossible feature prior to insertion into a delivery tube, and FIG. 19shows the FIG. 18 structure after insertion into delivery tube 40. Acomparison of FIG. 7 or 10, on the one hand, with FIG. 19, on the otherhand, reveals that in FIG. 19 fingers 14 form a more nearly cylindricalarray at each axial end of medial portion 16 because the flexuralstiffness of the fingers in FIGS. 18 and 19 has been tailored to producethis result.

[0065]FIGS. 20 and 21 show illustrative techniques for tailoring theflexural stiffness of fingers 14 along their length as mentioned abovein connection with FIGS. 18 and 19. In FIG. 20 the thickness of the wallof the starting tube 10′ is varied along the length of the tube to givefingers 14 correspondingly varied thickness along their lengths. In FIG.21 fingers 14 are cut so that their width varies along their length. Ifdesired both techniques (FIG. 20 and FIG. 21) can be combined. Ingeneral terms, the geometry of fingers 14 can be tailored in anysuitable way to cause fingers 14 to exhibit any desired elasticbehavior.

[0066]FIG. 22 illustrates another technique for attaching natural orartificial graft conduit 30 to a connector in accordance with thisinvention. As shown in FIG. 22 the fingers 14 at one end of medialportion 16 are made to pass through (e.g., by piercing) an annular endportion of graft conduit 30. When the connector and graft are installedin the patient through an aperture in the patient's body tissue wall 52,these fingers 14 curve back to contact one surface of wall 52, while thefingers 14 at the other end of medial portion 16 curve back to contactthe other surface of wall 52.

[0067]FIG. 23 illustrates another point that has already been mentionedbriefly; namely, that an end of a connector of this invention can havean angle other than 90° to the longitudinal axis of the connector. Inthe example shown in FIG. 23 the left-hand end of the connector is notperpendicular to the longitudinal axis of the connector. This type ofconnector may be particularly suitable for connecting a graft conduit tothe sidewall of another conduit at an angle which is not perpendicularto the longitudinal axis of the other conduit.

[0068]FIG. 24 illustrates a technique that may be used to releasablyhold fingers 14 in a desired configuration prior to deployment of aconnector or plug in a patient. In this embodiment the free end portionof each finger 14 near one end of the connector or plug has a hole 14 cthrough it. A wire 90 or other suitable material strand is threadedthrough these holes and formed into a loop that holds the fingers in adesired condition (in this case, a substantially cylindrical extensionof medial portion 16). When loop 90 is undone and pulled out of holes 14c, the associated fingers 14 are released to spring radially out (e.g.,as shown in FIG. 8 or FIG. 12). This type of releasable retention offingers 14 can be used in place of or in addition to retention inside adelivery tube (e.g., tube 40 in FIG. 7 or 10) to facilitate control ofthe associated fingers until it is desired to fully deploy them. Forexample, such releasable confinement and control of fingers 14 may beuseful to facilitate intraluminal delivery and deployment of a connectoror plug.

[0069]FIG. 25 shows another example of a structure 100 for releasablyconfining fingers 14 on a connector. In this case structure 100 is anelongated tube or rod which extends axially through the connector. Asomewhat enlarged head 102 on one end of structure 100 includes a recess104 for releasably receiving the free ends of the fingers 14 at one endof medial portion 16. In other words, recess 104 defines a collar 106that extends annularly around the adjacent free ends of fingers 14. Whenfingers 14 are thus received in recess 104 or collar 106, they areprevented from springing radially outwardly. However, when fingers 14are released from recess 104 or collar 106 (e.g., by shifting structure100 to the left relative to the other elements shown in FIG. 25), thefingers are free to resiliently spring radially outwardly. Structure 100can then be removed (e.g., by pulling it back to the right as viewed inFIG. 25). Head 102 may additionally be sharply pointed as shown in FIG.25 to act as an incisor and/or dilator for helping the structure to passthrough a patient's body tissue wall prior to release of fingers 14 fromrecess 104 or collar 106. Structure 100 may be adapted for passage intoa patient along a guide wire previously installed in the patient. Forexample, structure 100 may have a central, axially extending bore orlumen through which such a guide wire may pass. A central, axiallyextending guide structure may similarly be used with embodiments likethe one shown in FIG. 7.

[0070]FIG. 26 shows possible modification of a connector in accordancewith the invention to include a web 110 of a highly elastic materialsuch as silicone between adjacent fingers 14. Such a web 110 can beprovided on the fingers 14 at either or both ends of medial portion 16.Possible benefits of web 110 include enhanced sealing and fasterclotting. If desired, a clot-enhancing or clot-promoting material ordrug can be added to web 110.

[0071] Although not always specifically mentioned above, it will beunderstood that many of the features shown in FIGS. 14-26 are applicableto plugs as well as to graft connectors.

[0072]FIGS. 27 and 28 show an alternative embodiment in which aconnector is assembled from two initially separate parts 10 x and 10 y.Each of parts 10 x and 10 y is preferably formed from a tube similar tothe tube shown in FIGS. 1 and 2. The diameter of the tube used to formpart 10 y is somewhat larger than the diameter of the tube used to formpart 10 x. Fingers 14 x and 14 y are formed in one axial end portion ofeach tube. Holes 120 x and 120 y are formed in the other axial endportion of each tube. A medial portion 16 x and 16 y remains in eachtube between the fingers 14 and the holes 120 of that tube. The fingers14 on each tube are treated as described above for other embodiments(i.e., the fingers are deflected radially out and set in thatcondition).

[0073] Structures 10 x and 10 y are then assembled on an end of a graftconduit 30 as shown in FIG. 28. In particular, the perforated and medialportions of structure 10 y are placed substantially concentricallyaround the outside of graft conduit 30, while structure 10 x is placedsubstantially concentrically inside the graft conduit. Structures 10 xand 10 y are oriented so that their fingers 14 are oppositely directedalong the longitudinal axis of graft conduit 30. Structures 10 x, 10 y,and 30 are secured together (e.g., by sutures 130 through radiallyadjacent holes 120 x and 120 y and the intervening wall material ofconduit 30). As an alternative or addition to suturing, structures 10 x,10 y, and 30 may be press fit together, and/or an adhesive may be usedto help hold these components together. Fingers 14 may be resilientlydeflected substantially parallel to the longitudinal axis of conduit 30and away from the region of holes 120 if that will facilitate assemblyof structures 10 x and 10 y on conduit 30. The assembly of structures 10x, 10 y, and 30 may be delivered to and installed at a graft site in apatient in the same manner as is described above for any of the otherconnector embodiments.

[0074] Connectors of the type shown in FIGS. 27 and 28 may have theadvantage that, even though one component 10 x is inside conduit 30,that component can be radially recessed into conduit 30 as indicated at30 x, thereby leaving a substantially smooth passageway for fluid flowthrough conduit 30 and the connector. Such a smooth passageway isdesirable for such purposes as avoiding any obstruction or disturbance(e.g., by causing turbulence) of the fluid flow. The recessing at 30 xcan be produced by clamping the tissue between the tubular portions ofcomponents 10 x and 10 y.

[0075] In some applications it might be possible to use only onestructure like 10 x or 10 y in a graft connector. For example, it mightbe possible to eliminate structure 10 y from FIG. 28. In addition, ifstructure 10 y is eliminated from FIG. 28, the assembly shown in FIG. 28could be further modified by placing structure 10 x outside rather thaninside the end of graft conduit 30. Any of the modifications and/orenhancements described above for other connector embodiments can also beapplied to connectors of the type shown in FIGS. 27 and 28.

[0076] Structures of the type shown in FIGS. 27 and 28 are also usableto make plugs in accordance with this invention. For example, astructure like 10 x may be assembled with a structure like 10 ygenerally as shown in FIG. 28, but without graft conduit 30. Theinterior of the assembly would be occluded by a plugging material orstructure, generally as shown at 70 in FIG. 9, to produce a completedplug. Such a plug would be installed as described above for any of theother plug embodiments.

[0077] It will be understood that the foregoing is only illustrative ofthe principles of the invention, and that still other modifications canbe made by those skilled in the art without departing from the scope andspirit of the invention. For example, the various materials anddimensions mentioned herein are only examples, and other materials anddimensions can be used if desired. As another example of modificationswithin the scope of the invention, as an alternative to starting with atube like tube 10 in FIGS. 1 and 2, one could start with a web of anymaterial that would be suitable for tube 10. Two opposite marginalportions of the web would then be cut at numerous substantially parallellocations (somewhat like cuts 12 in FIG. 3), leaving an uncut medial webportion. Medial web portion would then be formed into a medial tubeportion (like 16 in FIG. 3), e.g., by forming it around a mandrel, withor without bonding of the resulting seam. The structure would then besubstantially as shown in FIG. 3 and could be further processed and usedto produce a connector or plug as described above in connection with anyof the subsequent FIGS. Similar web rather than tube starting structurescould be used for embodiments of the type shown in FIGS. 27 and 28.

The invention claimed is:
 1. A connector for use in connecting an end ofa tubular graft conduit to a side wall of a patient's tubular bodyconduit via an aperture in that side wall comprising: a medial tubularportion; and a plurality of resilient fingers integral with the medialtubular portion and extending substantially radially out from an axialend of the medial tubular portion.
 2. The connector defined in claim 1wherein the medial tubular portion and the fingers comprise nitinol. 3.A graft assembly comprising: a tubular graft conduit; and a connector asdefined in claim 1 substantially coaxially connected to an end portionof the tubular graft conduit.
 4. The graft assembly defined in claim 3wherein the end portion of the tubular graft conduit is disposedsubstantially coaxially inside the medial tubular portion.
 5. A graftinstalling assembly comprising: a graft assembly as defined in claim 3;and a delivery structure disposed substantially coaxially around thegraft assembly, whereby the fingers are elastically deflected inwardlytoward parallelism with a central longitudinal axis of the medialtubular portion.
 6. The connector defined in claim 1 wherein the fingersinclude fingers that extend substantially radially out from each axialend of the medial tubular portion.
 7. The connector defined in claim 1wherein the medial tubular portion is perforated.
 8. The connectordefined in claim 7 wherein the perforations of the medial tubularportion increase flexibility of the medial tubular portion.
 9. Theconnector defined in claim 7 wherein the perforations of the medialtubular portion increase radial flexibility of the medial tubularportion.
 10. The connector defined in claim 7 wherein the perforationsof the medial tubular portion provide sites for attachment of theconnector to the tubular graft conduit.
 11. The connector defined inclaim 1 wherein end portions of the fingers remote from the medialtubular portion are pointed.
 12. The connector defined in claim 1wherein end portions of the fingers remote from the medial tubularportion are barbed.
 13. The connector defined in claim 1 wherein thefingers are concave curved as viewed from a plane extending radially outfrom the medial tubular portion.
 14. The connector defined in claim 1wherein the medial tubular portion has a substantially round crosssection.
 15. The connector defined in claim 1 wherein the medial tubularportion has a substantially elliptical cross section.
 16. The connectordefined in claim 1 wherein substantially all of the fingers extendingfrom an axial end of the medial tubular portion are of substantiallysimilar length.
 17. The connector defined in claim 1 wherein differentones of the fingers extending from an axial end of the medial tubularportion are of different lengths.
 18. The connector defined in claim 6wherein the fingers that extend from both axial ends of the medialtubular portion are of substantially similar length.
 19. The connectordefined in claim 6 wherein the fingers that extend from one axial end ofthe medial tubular portion are different in length from the fingers thatextend from the other axial end of the medial tubular portion.
 20. Theconnector defined in claim 15 wherein the elliptical cross section has arelatively large major axis and a relatively small minor axis, andwherein ones of the fingers that extend radially out more nearlyparallel to the major axis than to the minor axis are longer than othersof the fingers that extend radially out more nearly parallel to theminor axis than to the major axis.
 21. The connector defined in claim 6wherein free end portions of the fingers that extend from one axial endof the medial tubular portion overlap free end portions of the fingersthat extend from the other axial end of the medial tubular portion. 22.The connector defined in claim 1 wherein each finger has differentflexural stiffness radially of the medial tubular portion at differentpoints along the length of the finger.
 23. The connector defined inclaim 1 wherein each finger has different thickness at different pointsalong its length.
 24. The connector defined in claim 1 wherein eachfinger has different width at different points along its length.
 25. Theconnector defined in claim 3 wherein the fingers extend through aportion of the side wall of the tubular graft conduit.
 26. The connectordefined in claim 1 wherein the axial end of the medial tubular portiondefines a plane which is transverse but not perpendicular to alongitudinal axis of the medial tubular portion.
 27. The connectordefined in claim 1 further comprising structure on free end portions ofthe fingers and configured to facilitate releasable retention of thefingers in a condition in which they extend substantially parallel to alongitudinal axis of the medial tubular portion.
 28. The connectordefined in claim 27 wherein the structure comprises an aperture througheach of the fingers.
 29. A graft installing assembly comprising: a graftassembly as defined in claim 3; and a delivery structure extendingsubstantially coaxially through the graft assembly and including acollar configured to releasably retain the fingers in a condition inwhich they extend substantially parallel to a longitudinal axis of themedial tubular portion.
 30. The graft installing assembly defined inclaim 29 wherein the delivery structure is axially shiftable relative tothe graft assembly in order to shift the collar out of engagement withthe fingers and thereby release the fingers to extend substantiallyradially out from the medial tubular portion.
 31. The graft assemblydefined in claim 29 wherein the delivery structure includes asubstantially conical tip extending away from the fingers and configuredto facilitate entry of the graft assembly into an aperture in apatient's body tissue.
 32. The connector defined in claim 1 furthercomprising: an elastic web between adjacent ones of the fingers.
 33. Theconnector defined in claim 32 wherein the web comprises silicone. 34.The connector defined in claim 1 further comprising: a second medialtubular portion; and a second plurality of resilient fingers integralwith the second medial tubular portion and extending radially out froman axial end of the second medial tubular portion, the second medialtubular portion being configured to receive an axial end portion of thetubular graft conduit substantially coaxially inside the second medialtubular portion with the medial tubular portion received substantiallycoaxially inside the axial end portion.
 35. The connector defined inclaim 34 wherein the second medial tubular portion is further configuredso that when the second medial tubular portion receives the axial endportion of the tubular graft conduit with the medial tubular portionreceived substantially coaxially inside the axial end portion, thefingers on the medial tubular portion extend out of the axial endportion and the second fingers on the second medial tubular portionextend in a direction which is generally away from the fingers on themedial tubular portion.
 36. The connector defined in claim 34 whereinthe medial tubular portion and the second medial tubular portion includestructures configured to facilitate securing those portions relative toone another.
 37. The connector defined in claim 36 wherein thestructures are further configured to facilitate securing the medialtubular portion and the second medial tubular portion relative to theaxial end portion.
 38. The connector defined in claim 36 wherein thestructures comprise apertures through side walls of the medial tubularportion and the second medial tubular portion.
 39. The connector definedin claim 38 wherein the apertures are configured to receive suturestrands passed through those apertures and the axial end portion.
 40. Aplug for use in plugging an aperture through a patient's body structurecomprising: a medial tubular portion; a plurality of resilient fingersintegral with the medial tubular portion and extending substantiallyradially out from an axial end of the medial tubular portion; and aplugging structure substantially occluding the medial tubular portion.41. The plug defined in claim 40 wherein the medial tubular portion andthe fingers comprise nitinol.
 42. A plug installing assembly comprising:a plug as defined in claim 40; and a delivery structure disposedsubstantially coaxially around the plug, whereby the fingers areelastically deflected inwardly toward parallelism with a centrallongitudinal axis of the medial tubular portion.
 43. The plug defined inclaim 40 wherein the fingers include fingers that extend substantiallyradially out from each axial end of the medial tubular portion.
 44. Theplug defined in claim 40 wherein end portions of the fingers remote fromthe medial tubular portion are pointed.
 45. The plug defined in claim 40wherein end portions of the fingers remote from the medial tubularportion are barbed.
 46. The plug defined in claim 40 wherein the fingersare concave curved as viewed from a plane extending radially out fromthe medial tubular portion.
 47. The plug defined in claim 40 wherein themedial tubular portion has a substantially round cross section.
 48. Theplug defined in claim 40 wherein the medial tubular portion has asubstantially elliptical cross section.
 49. The plug defined in claim 40wherein substantially all of the fingers extending from an axial end ofthe medial tubular portion are of substantially similar length.
 50. Theplug defined in claim 40 wherein different ones of the fingers extendingfrom an axial end of the medial tubular portion are of differentlengths.
 51. The plug defined in claim 43 wherein free end portions ofthe fingers that extend from one axial end of the medial tubular portionoverlap free end portions of the fingers that extend from the otheraxial end of the medial tubular portion.
 52. The plug defined in claim40 wherein each finger has different flexural stiffness at differentpoints along its length.
 53. The plug defined in claim 40 wherein eachfinger has different thickness at different points along its length. 54.The plug defined in claim 40 wherein each finger has different width atdifferent points along its length.
 55. The plug defined in claim 40further comprising structure on free end portions of the fingers andconfigured to facilitate releasable retention of the fingers in acondition in which they extend substantially parallel to a longitudinalaxis of the medial tubular portion.
 56. The plug defined in claim 55wherein the structure on free end portions of the fingers comprises anaperture through each of the fingers.
 57. The plug defined in claim 40further comprising: an elastic web between adjacent ones of the fingers.58. The plug defined in claim 57 wherein the web comprises silicone. 59.The method of making a medical graft connector comprising: providing atube of an elastic material; substantially axially cutting an axial endportion of the tube at a plurality of locations spaced circumferentiallyaround the axial end portion to convert the axial end portion to aplurality of fingers that extend substantially axially from an adjacentend of an uncut medial portion of the tube; deflecting the fingerssubstantially radially out from the medial portion; and setting thefingers as deflected in the deflecting.
 60. The method defined in claim59 wherein the setting comprises: heat treating the fingers.
 61. Themethod of making a medical graft assembly comprising: making a medicalgraft connector by the method defined in claim 59; and substantiallycoaxially attaching the medical graft connector to a tubular graftconduit.
 62. The method of making an assembly for installing a medicalgraft comprising: making a medical graft assembly by the method definedin claim 61; and substantially coaxially surrounding the medical graftassembly with a delivery structure which elastically deflects thefingers inwardly toward parallelism with a central longitudinal axis ofthe medial tubular portion.
 63. The method of installing a medical graftcomprising: providing an assembly for installing a medical graft by themethod defined in claim 62; inserting the delivery structure through anaperture in a side wall of a patient's tubular body conduit; andshifting the delivery structure relative to the medical graft assemblyand the tubular body conduit so that the delivery structure is removedfrom the aperture but the medical graft connector is left extendingthrough the aperture with the fingers again extending substantiallyradially out from the medial portion inside the tubular body conduit.64. The method defined in claim 59 further comprising: substantiallyaxially cutting a second axial end portion of the tube remote from theaxial end portion at a second plurality of locations spacedcircumferentially around the second axial end portion to convert thesecond axial end portion to a second plurality of second fingers thatextend substantially axially from an adjacent second end of the uncutmedial portion of the tube; deflecting the second fingers substantiallyradially out from the medial portion; and setting the second fingers asdeflected in the deflecting of the second fingers.
 65. The methoddefined in claim 59 further comprising: perforating the medial portion.66. The method defined in claim 59 further comprising: pointing freeends of the fingers.
 67. The method defined in claim 59 furthercomprising: barbing free end portions of the fingers.
 68. The methoddefined in claim 59 wherein the deflecting comprises: concave curvingthe fingers as viewed from a plane extending radially out from themedial portion.
 69. The method defined in claim 59 wherein the tube isprovided with a substantially round cross section.
 70. The methoddefined in claim 59 wherein the tube is provided with a substantiallyelliptical cross section.
 71. The method defined in claim 64 wherein thedeflecting of the fingers and the deflecting of the second fingers causefree end portions of the fingers to overlap with free end portions ofthe second fingers.
 72. The method defined in claim 59 wherein the tubeis provided with different wall thickness at different locations alongits length.
 73. The method defined in claim 59 wherein the cuttingcauses each finger to have different width at different locations alongits length.
 74. The method defined in claim 59 wherein the tube isprovided with an axial end which is transverse but not perpendicular toa longitudinal axis of the tube.
 75. The method defined in claim 59further comprising: providing structure on free end portions of thefingers configured to facilitate releasable retention of the fingers ina condition in which they extend substantially parallel to alongitudinal axis of the medial portion.
 76. The method of making anassembly for installing a medical graft comprising: making a medicalgraft assembly by the method defined in claim 61; and placing aremovable structure around the fingers to releasably retain the fingersin a condition in which they extend substantially parallel to alongitudinal axis of the medial portion.
 77. The method of installing amedical graft comprising: providing an assembly for installing a medicalgraft by the method defined in claim 76; inserting the assembly forinstalling a medical graft part way through an aperture in a side wallof a patient's tubular body conduit so that the fingers are inside thetubular body conduit; and removing the structure from around the fingersso that the fingers can again extend radially out from the medialportion inside the tubular body conduit.
 78. The method defined in claim59 further comprising: providing an elastic web between adjacent ones ofthe fingers.
 79. The method defined in claim 59 further comprising:providing a second tube of an elastic material; substantially axiallycutting an axial end portion of the second tube at a second plurality oflocations spaced circumferentially around the axial end portion of thesecond tube to convert that axial end portion to a second plurality ofsecond fingers that extend substantially axially from an adjacent end ofan uncut second medial portion of the second tube; deflecting the secondfingers substantially radially out from the second medial portion;setting the second fingers as deflected in the deflecting of the secondfingers; and assembling the medial portion substantially concentricallyinside an axial end section of a tubular graft conduit and the secondmedial portion substantially concentrically outside the axial endsection.
 80. The method defined in claim 79 wherein the assembling isperformed so that the fingers extend out of the axial end section and sothat the second fingers extend in a direction which is generally awayfrom the fingers extending out of the axial end section.
 81. The methoddefined in claim 79 wherein the assembling comprises: securing themedial portion and the second medial portion relative to one another viathe axial end section.
 82. The method defined in claim 81 wherein thesecuring comprises: suturing the medial portion and the second medialportion to one another through the axial end section.
 83. The method ofmaking a medical plug comprising: providing a tube of an elasticmaterial; substantially axially cutting an axial end portion of the tubeat a plurality of locations spaced circumferentially around the axialend portion to convert the axial end portion to a plurality of fingersthat extend substantially axially from an adjacent end of an uncutmedial portion of the tube; deflecting the fingers substantiallyradially out from the medial portion; setting the fingers as deflectedin the deflecting; and occluding the medial portion.
 84. The methoddefined in claim 83 wherein the setting comprises: heat treating thefingers.
 85. The method of making an assembly for installing a medicalplug comprising: making a medical plug by the method defined in claim83; and substantially coaxially surrounding the medical plug with adelivery structure which elastically deflects the fingers inwardlytoward parallelism with a central longitudinal axis of the medialportion.
 86. The method of installing a medical plug comprising:providing an assembly for installing a medical plug by the methoddefined in claim 85; inserting the delivery structure through anaperture in a patient's body tissue; and shifting the delivery structurerelative to the medical plug and the body tissue so that the deliverystructure is removed from the aperture but the medical plug is leftextending through the aperture with the fingers extending substantiallyradially out from the medial portion on one side of the body tissue. 87.The method defined in claim 83 further comprising: substantially axiallycutting a second axial end portion of the tube at a second plurality oflocations spaced circumferentially around the second axial end portionto convert the second axial end portion to a second plurality of secondfingers that extend substantially axially from an adjacent end of themedial portion; deflecting the second fingers substantially radially outfrom the medial portion; and setting the second fingers as deflected inthe deflecting of the second fingers.
 88. The method of making anassembly for installing a medical plug comprising: making a medical plugby the method defined in claim 87; and substantially coaxiallysurrounding the medical plug with a delivery structure which elasticallydeflects the fingers and the second fingers inwardly toward parallelismwith a central longitudinal axis of the medial portion.
 89. The methodof installing a medical plug comprising: providing an assembly forinstalling a medical plug by the method defined in claim 88; insertingthe delivery structure through an aperture in a patient's body tissue;and shifting the delivery structure relative to the medical plug and thebody tissue so that the delivery structure is removed from the aperturebut the medical plug is left extending through the aperture with thefingers again extending radially out from the medial portion on one sideof the body tissue and the second fingers again extending radially outfrom the medial portion on an opposite side of the body tissue.
 90. Themethod defined in claim 83 further comprising: pointing free ends of thefingers.
 91. The method defined in claim 83 further comprising: barbingfree end portions of the fingers.
 92. The method defined in claim 83wherein the deflecting comprises: concave curving the fingers as viewedfrom a plane extending radially out from the medial portion.
 93. Themethod defined in claim 83 wherein the tube is provided with asubstantially round cross section.
 94. The method defined in claim 83wherein the tube is provided with a substantially elliptical crosssection.
 95. The method defined in claim 87 wherein the deflectingcauses free end portions of the fingers to overlap with free endportions of the second fingers.
 96. The method defined in claim 83wherein the tube is provided with different wall thickness at differentlocations along its length.
 97. The method defined in claim 83 whereinthe cutting causes each finger to have different width at differentlocations along its length.
 98. The method defined in claim 83 furthercomprising: providing structure on free end portions of the fingersconfigured to facilitate releasable retention of the fingers in acondition in which they extend substantially parallel to a longitudinalaxis of the medial portion.
 99. The method of making an assembly forinstalling a medical plug comprising: making a medical plug by themethod defined in claim 83; and placing a removable structure around thefingers to releasably retain the fingers in a condition in which theyextend substantially parallel to a longitudinal axis of the medialportion.
 100. The method of installing a medical plug comprising:providing an assembly for installing a medical plug by the methoddefined in claim 99; inserting the assembly for installing a medicalplug part way through an aperture in a patient's body tissue so that thefingers extending from one end of the medial portion pass through theaperture; and removing the structure from around the fingers that extendfrom said one end of the medial portion so that those fingers can againextend radially out from the medial portion and engage tissue around theaperture.
 101. The method defined in claim 83 further comprising:providing an elastic web between adjacent ones of the fingers.